Transparent hard coatings, such as, for example, silicon oxycarbide, may have a glass like appearance and an abrasion resistance and weatherability that may be superior to many plastic (or polymer) substrates. Plasma enhanced chemical vapor deposition may be used to deposit the hard coating. When deposited directly on a bare plastic substrate, the adhesion of the hard coating to the substrate, and the optical properties of the coated substrate, may be limited. A base layer may be included between the substrate and the hard coating to improve the adhesion of the hard coating to the substrate and/or to improve the optics of the coated substrate.